Rough sex pornography is similar to pornography featuring sadomasochism, and typically features a Top who humiliates and/or degrades a Bottom while being physically violent towards them. Interracial pornography typically employs ethnic and racial stereotypes in its depiction of performers and many of interracial pornographic films still include racial stereotypes, although the segregation of actors by race has diminished considerably. They cited the Internet and text messaging as common hentai videos ways of organising meetings. Lesbianism has been a theme in erotic art since at least the time of ancient Rome, and many regard depictions of lesbianism to be erotic. One-sided male nudity can also arise when a male disrobes as part of a male striptease. It may also involve touching, rubbing, or pinching the nipples or other erogenous zones while masturbating. Internal ejaculations, followed by images of semen dripping from the anus, are sometimes depicted in bareback gay pornography, where they are referred to by the term breeding or the reverse money shot. It is suggested that much of the obscurity and the uncertainties about female ejaculation are related to mixing up these two phenomena. Fisting pornography features the insertion of an entire hand into a performer vagina or anus. There is also some evidence that pornography can be used to treat voyeurism. Babysitter pornography features usually teenage girls being exploited and having taboo sex with older, male employers. Consent is the most important criterion here. It is sometimes described as a sexual fantasy, by women or men, depicting an exhibitionist or physique worship scenario. Snuff pornography involves the gay bear porn actual death of any of the participants, consenting or otherwise, simulated death is not considered snuff. These scenes may either have the cameraman directly engaging in sex or merely filming others having sex. The buttocks in human females thus contain more adipose tissue than in males, especially after puberty. Pornography is generally classified as either softcore or hardcore pornography.